Fluorine-containing polymers (also known as “fluoropolymers”) are a commercially useful class of materials. Fluoropolymers include, for example, crosslinked fluoroelastomers and semi-crystalline or glassy fluoropolymers. Fluoropolymers are generally of high thermal stability and are particularly useful at high temperatures. They may also exhibit extreme toughness and flexibility at very low temperatures. Many of these fluoropolymers are almost totally insoluble in a wide variety of solvents and are generally chemically resistant. Some have extremely low dielectric loss and high dielectric strength, and may have unique non-adhesive and low friction properties. Fluoroelastomers, particularly the copolymers of vinylidene fluoride with other ethylenically unsaturated halogenated monomers such as hexafluoropropylene, have particular utility in high temperature applications such as seals, gaskets, and linings.
Multi-layer constructions containing a fluoropolymer enjoy wide industrial application. Such constructions find utility, for example, in fuel line hoses and related containers and hoses or gaskets in the chemical processing field. Adhesion between the layers of a multi-layered article may need to meet various performance standards dependent on the use of the finished article. However, it is often difficult to establish high bond strengths when one of the layers is a fluoropolymer, in part because of the non-adhesive qualities of fluoropolymers. Various methods have been proposed to address this problem. One approach is to use an adhesion promoter between the fluoropolymer layer and the second polymer layer. Amines and aminosilanes have been used as adhesion promoters. Surface treatments for the fluoropolymer layer, including the use of powerful reducing agents (e,g., sodium naphthalide) and corona discharge, have also been employed to enhance adhesion. In the case of fluoropolymers containing interpolymerized units derived from vinylidene fluoride, exposure of the fluoropolymer to a dehydrofluorinating agent such as a base has been used.
There is a need for improved amino functional polymeric bonding compositions that can be created from conventional readily available commercial non-fluoropolymers by a simple and economical reaction while retaining the valuable properties of the starting polymers, yet also allow bonding to difficult-to-bond substrates such as THV, PVDF and ETFE fluoropolymers. It is well known that the Si—N or Si—S bonds are weaker than the Si—O bond. Therefore Si is bonded predominantly to oxygen rather than nitrogen in the inventive polymers.